The Collaborative International Dictionary of English v.0.48:

Brown thrush \Brown" thrush"\ (Zool.)
   A common American singing bird (Harporhynchus rufus),
   allied to the mocking bird; -- also called brown thrasher.
   [1913 Webster]

WordNet (r) 3.0 (2006):

brown thrasher
    n 1: common large songbird of eastern United States having
         reddish-brown plumage [syn: brown thrasher, brown
         thrush, Toxostoma rufums]